Using a Rotary Encoder

As part of an ongoing project, I recently designed an expander card for my ESP-12E I2C Base. I am referring to this device( Atmega 328P Base PWM Controller Card). At the time of writing that article, I have not released any of the code for the project. This is a very short post, showing one possible way to implement a rotary encoder onto that particular device. (It can also be adapted for other devices, of course)

Arduino Style Code for using a rotary encoder

// Constants and Variables
const int encFWD = 8;
const int encREV = 7;
int aState;
int aLastState;
int encDir;
int encTurned = LOW;
int encLastState;
int encValue = 0;
int lastEncValue;
const int encInc = 10;

unsigned long lastEncDebounce = 0;
unsigned encDebounceDelay = 50;
const int encBtn = 9;
int encButtonState;
int lastEncBtnState = LOW;
int EncBtnValue = LOW;
int encBtnState;

void setup() {
  //Rotary Encoder
  pinMode(encFWD,INPUT_PULLUP);
  pinMode(encREV,INPUT_PULLUP);
  pinMode(encBtn,INPUT_PULLUP);
  // Init the pins in UNPUT Pullup Mode
  encTurned = LOW; // Flag for encoder

  encLastState = digitalRead(encFWD);
  //Serial
  Serial.begin(115200);
  //Status LED on D13
  pinMode(13,OUTPUT);
  digitalWrite(13,LOW);
}

void loop() {
  lastEncValue = encValue;
 //Handle the Encoder Push Button
 encBtnState = digitalRead(encBtn);
 if (encBtnState != lastEncBtnState) {
    lastEncDebounce = millis();
 }
 if ((millis() - lastEncDebounce) > encDebounceDelay) {
    if (encBtnState != encButtonState) {
        encButtonState = encBtnState;
        if (lastEncBtnState == LOW) {
          EncBtnValue = !EncBtnValue; // Toggle the button Value
        }
    }
 }
 lastEncBtnState = encBtnState;
 // Handle the Rotary Encoder Dial
 aState = digitalRead(encFWD);
 if (aState != aLastState) {
    if (digitalRead(encREV) != aState) {
       if (encTurned == LOW) {
          encLastState = encTurned;
          encTurned = HIGH; // Set Flag
// Setting this flag will get rid of double value entries caused by contact
// bounce inside the encoder. I found it easier to implement this way
// as opposed to using software debouncing as with the button

       } else {
          encTurned = LOW; // Set Flag low
// This will ensure that the value is increased only once per "click"
       }
       if ((encValue < 300) && (encDir == 0)){
          if ((encLastState == LOW) && (encTurned == HIGH)){
            encValue = encValue + encInc;
            encDir = 1;
          }
       }
      
    } else {
      if (encTurned == LOW) {
        encLastState = encTurned;
        encTurned = HIGH;  
      } else {
        encTurned = LOW;
      }
      if ((encValue > 0) && (encDir == 0)){
          if ((encLastState == LOW) && (encTurned == HIGH)){
            encValue = encValue - encInc;
            encDir = 2;
          }
      }
    }
    encLastState = encTurned;
}
aLastState = aState;
encDir = 0;
// Print Some Status
if (encValue != lastEncValue) {
  Serial.print("Encoder Value Changed from ");
  Serial.print(lastEncValue);
  Serial.print(" to ");
  Serial.println(encValue);
}
digitalWrite(13,EncBtnValue);



}

I hope that this will be useful to somebody.

I2C IO Card for ESP-12E I2C Base Card

The I2C IO Card for ESP-12E I2C Base Card is another expander card for the ESP-12E I2C Base Card Project. This PCB is an address-selectable I2C module with two relays and six (6) GPIO pins, all driven from a single PCF8574 running at 3v. The relays are optically isolated, and generous mains isolation cutouts were provided to reduce the possibility of mains voltage tracking. A jumper to enable/disable the i2c pullup-resistors is also provided on the PCB.

The relays are powered from a single LDO regulator, accepting 12v DC from the 2x20pin female header on the bottom of the card. 3.3v and ground should also be applied to the card at the 2x20pin header.

It is worth mentioning that this circuit does not contain level converting circuitry and that the i2c bus thus runs at 3.3v to be compatible with ESP chips.

It is possible to use the card with other processors if the appropriate level converters are used on the i2c bus.

The Schematic

Manufacturing the PCB


Over the past eight years, PCBWay has continuously upgraded their MANUFACTURING plants and equipment to meet higher quality requirements, and now THEY also provide OEM services to build your products from ideas to mass production and access to the market.


The PCB for this project has been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to have manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5 USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

ESP-12E I2C Base Card

As a follow-up on the ESP-12E Card, today we will look at the prototype base card that this was designed to slot into – The ESP-12E I2c Base Card.

Initial Features ( To be expanded in future versions )

4 x 40Pin Expansion slots, with access to 12v, 3.3v and Gnd on each slot.
2 x “IRQ” pins per slot ( serviced by a single PCF8574 )
I2C bus access on each slot (3.3v )
UART Header
Reset and Flash Header
GPIO Header ( Direct access to the ESP-12E GPIO Pins )
Analog Input Header (a Single input – A0, as per ESP-12E limitation)
Buck Converter Power Supply Module, capable of up to 2A of current

ESP-12E I2C Base Card – Top view

The Schematic

Schematic

The PCB – some pictures

ESP 12-E Card with Base Board

Manufacturing the PCB


Over the past eight years, PCBWay has continuously upgraded their MANUFACTURING plants and equipment to meet higher quality requirements, and now THEY also provide OEM services to build your products from ideas to mass production and access to the market.


The PCB for this project has been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to have manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5 USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

ESP-12E Card

A few months ago, I started working on an MCU Card design, which borrows from the idea of a standard desktop PC, in which there are a main-board, MCU and expansion slots, to add and remove peripherals as needed quickly.

The ESP-12E Card is a continuation of that project, with the ultimate goal to have a universal “main-board” that can accept various MCUs and standardised “expansion modules” that perform a specific task.

ESP-12E Card
ESP-12E Card

The PCB

The ESP-12E Card contains the bare minimum components to allow the chip to function. There are no power regulators or USB-to-TTL converters onboard. Code is flashed via an external USB-to-TTL converter, with Flash and Reset buttons on the actual PCB, or available in the 2×20 Pin female header at the bottom of the card.

Most of the GPIO is also broken out to the 2×20 pin header, with the exception of the 6 GPIO that is usually connected to the internal Flash on the ESP-12E module.

I have made provision for enough power and ground pins on the header as well.

As far as GPIO is concerned, They have been grouped together by function, as much as possible at least, to make interfacing with the base-board as easy as possible.

The Schematic

ESP-12E Card Schematic

The schematic is not complicated. It is a standard ESP-8266 configuration, with all non-essential components removed.

The “base-board” ( a sneak preview )

Sneak preview of the Base Card

In a future article, I will tell you more about this ( for the time being limited to I2C ) base card. [ a quick explanation: When I mean limited to I2C, it relates to the fact that at the moment, the base card, ( a prototype ) can only communicate back to the MCU via I2C protocol from each of the expansion slots, as well as via two dedicated IRQ lines from each slot ]Power is supplied via a small SMPS module.

Manufacturing the PCB


Over the past eight years, PCBWay has continuously upgraded their MANUFACTURING plants and equipment to meet higher quality requirements, and now THEY also provide OEM services to build your products from ideas to mass production and access to the market.


The PCB for this project has been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to have manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5 USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

Robotic Toy Car – Part 6

Today we will look at the remote control unit for the Robotic Toy Car – Part 6.
The project is close to being completed, and as such, there are quite a lot of final things that need to be taken care of.

One of these will definitely be the final coding, which I will release in the final part of the project, so with that in mind, let us take a look at the remote control unit.

Remote Control Unit, designed to be used with ESP-Now

I have decided to do something completely different from standard remote control units, being that I will use ESP-Now, a protocol developed by Espressif.
ESP-Now runs on the Wifi hardware of the ESP8266 or ESP32 and is basically a peer-to-peer protocol, that does not require Wifi but can co-exist with it on the same device. Outdoors, ESP-Now has a range of about 100m, which should work very well for my intended use.

The Remote control, as designed, will have 4 dedicated buttons: forward, reverse, left and right, divided into two groups to make two-handed control easier, similar to a standard game controller. No input on either of the two groups will result in stopping the vehicle, in the case of forwards and backwards, and centring the steering, in the case of the left-right axis.

a 3D Rendered Image of the PCB, motion axis on SW1 and SW2, steering axis on SW3 and SW4

As I always try to make my designs somewhat reusable for other purposes, I have also broken out most of the unused GPIO pins to header pins, with also adding a jumper on GPIO16 to make deep-sleep wakeup mode possible., You can also re-use the switch pins for other purposes, just remember to first remove the 10k pull-up resistors at R14, R15, R16, and R17…

SW4 -> R16 , SW4 = GPIO4
SW3 -> R17 , SW3 = GPIO5
SW2 -> R15 , SW2 = GPIO13
SW1 -> R14 , SW1 = GPIO12

GPIO16 can be reused as well, just remove the jumper, but remember that it is pulled up through a LED and a 470ohm resistor…



There is no USB-to-serial converter onboard, I have been having quite a lot of headaches with them over the last few months, with almost all CH340G chips that I have purchased, being fake, or dead-on arrivals that don’t work… Sending them back to the suppliers, unfortunately, results in unpleasantries, because even placing them in verified working circuits, still proves them to be not working… This is however not an issue, as it is quite easy to upload the board with an external adapter.

The Schematic

Schematic Diagram

Manufacturing the PCB


Over the past eight years, PCBWay has continuously upgraded their MANUFACTURING plants and equipment to meet higher quality requirements, and now THEY also provide OEM services to build your products from ideas to mass production and access to the market.

The PCB for this project has been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to have manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.


Robotic Toy Car – Part 4

In this part of the series, Robotic Toy Car – Part 4, We will add some custom side-panels to the project. While the original toy did come with some laser cut aluminum side panels, I decided to replace them with PCB versions, with even more flashing lights (yes, this thing is turning into a “Christmas tree” , but that is what the eventual owner wanted… )

These side-panels will not be programmable. They will simply be operated from a standard 555 timer and a couple of other components, to give a flash time of about one second on and off each…

It is also an excellent project to showcase the capabilities of PCBWay, in dealing with a “rather difficult” PCB to manufacture. As you may know by now, I use PCBWay‘s services quite extensively, and I also only design my PCB’s with EasyEDA. EasyEDA is however quite limited in some aspects, and as far as myself, making panels of different designs on one PCB with complex shapes is not something that I do every day…

Let us take a look at what had to be done, and how well it was manufactured…

The PCB Layout

What we have here, is basically two mirrored side-panels ( as far as the visible “outside” is concerned anyway ) That consists of 6 led’s per side that will flash alternatively. On the “inside” we have a 555 timer chip, with some resistors and capacitors, as well as transistors that does the switching.

The Schematic

The difficulty of this PCB is definitely in the manufacturing. I was however pleasantly surprised with the excellent work that was done by PCBWay. Their Engineering staff did contact me early on in the order, with a suggested plan to manufacture, and once I approved that, they very quickly went on to production. My initial concern was that they suggested “mouse-bites” which we all know can sometimes come out a bit strange…

Completed PCB in packaging..

I was however extremely pleased when the above parcel arrived… They added side rails, and the “mouse-bytes” were super tiny.

After assembly ( not cleaned up yet )
After Assembly ( not cleaned up yet )
Installed on the toy car body

The “almost completed ” Robotic Toy Car

With the completion of the side-panels, it was also time to start work on the power wiring and other essential components of the project, which will get their own detailed post in a few days.

the “almost completed” project

Some details on the construction:
The toy originally came with a single 500mA 14500 cell, which unfortunately stopped working very soon after only a few uses… This was however one of the reasons why the entire project happened in the first place, so no complaints there.

I decided to replace it with a 18560 cell with a capacity of about 1900mA. This cell is much bigger however, and I had to think of where to place it. I decided to put it on the roof, sort of emulating a “spoiler”.

Some of the next parts of the project will be the remote control unit, which will basically be an ESP8266 running ESP-Now protocol, as well as a decent battery charging and power distribution circuit, that will protect the Lipo cell from over charging and discharging, as well as provide sufficient power for all the added electronics in the toy car.

“But you said it was Robotic, so why have a remote control?”

The initial plan for the project did indeed say robotic, but it is also designed to be a learning platform, especially to teach coding. With that in mind, it is definitely better to keep things simple for now, and add sensors and more capabilities later on, especially as I am actually planning to replace the main MCU board with a more powerful ESP32 in a next version anyway.

The car body is also extremely cramped, and does not have any space for mounting sensors at all. I plan to remedy that by designing and 3d-printing a whole new custom body shell later… providing that my young friend actually stays interested enough to learn the coding… If he doesn’t, he will as least have a very interesting looking custom remote controlled toy car.

Manufacturing the PCB

The PCB for this project is currently on its way from China, after having been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to be manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

Robot Toy Car – The Next steps

In our last project, we started working on repurposing an old toy car. In this part, Robot Toy Car – The next steps, we will take a look at the controller board for this project and discuss some of the problems that we have encountered up to now. Most of the various components for this project are still in the prototype stage, but It is quite important to get them tested to verify the final designs.

There are quite a few unique challenges in a project like this, which looks quite easy to solve but turn out to become quite challenging to get working just right in practice…

One of the most important, as well as the most frustrating part, turned out to be the H-Bridge Motor controller. The first prototype of this was introduced in the first part of this project. While functional on paper, as well as working quite well in real life, (when tested with an Arduino, as well as manually), It performs extremely poorly when used with the actual controller for this project, an ESP8266 12-E…

What could the reason be? How will I fix it…? The answers to that will be provided in a follow-up post. For now, let us take a look at the controller.

The unassembled ESP-8266 Controller board, straight from the factory
The Assembled ESP-8266 Controller board.

The Controller Board, details

Space inside the toy car is at a premium, so from the start, it was important to design a PCB that was small enough to fit, while also taking into consideration functionality, as well as all additional add-on components to ultimately be fitted to the project.

With this in mind, I have decided on the ESP-8266, which, while bigger than an Atmega328, does offer a few additional features, like WiFi, and ESP-Now, which will greatly help in controlling and even updating firmware OTA. The ESP-8266 does however also have a few serious flaws in this design, like limited useable GPIO pins, a 3.3v working voltage requirement, and quite high operating current requirements.

As the toy will likely not be used continuously, as well as the fact that it will run on batteries, which, can be replaced or recharged, I did not worry too much about the power issue. As far as the limited GPIO, that is where I2C comes in… It is quite easy to expand the GPIO with an IO Expander or two…

My main problem came in the form of the CH340G USB-to-UART converter chip. It seems like there must be quite a lot of counterfeit versions of these around, as none of the chips that I purchased, from many different suppliers, actually functioned, with the best one actually providing a USB port, but, when investigating with a logic analyser, the Rx and Tx lines of the UART, generating garbage…

Replacing it with a known working chip from a NodeMCU V1 board, magically solved the problem, verifying the PCB circuit as correct and working, and also proving that the purchased chips are definitely fake!

This was easily repaired by temporarily soldering jumper cables to the Rx and Tx lines on the ESP-8266, and using an external UART-to-USB converter to upload the initial sketch to the device. Future updates will be OTA, so not a problem in the long run anyway.

Controller Schematic

The controller schematic, above, is basically a rearranged stock NodeMCU v1 circuit, with the only difference being that only specific pins were broken out onto header pins. These will be used for controlling the two H-Bridges, and provide PWM as well as access to the I2C bus.

Software

Due to the fact that this controller is still definitely considered a prototype, my main focus is definitely on getting the control software sorted out first. That way, at least in my opinion, I can then focus on hardware issues responding to verified software inputs, without having to do both at the same time.

As mentioned before, I require OTA capability to upload new firmware to the device, so my starting point was the BasicOTA sketch provided with the Arduino IDE. This sketch was modified to perform some additional functionality, such as controlling the H-Bridges, PWM as well as a roof-mounted “status panel” with LED’s that also doubles as a visual display, to give a bit of colour to the project.

The “status panel” will be shown in a future post, however, with the only mention of it here being that it is I2C controlled, and based on a PCF8574.

The BasicOTA sketch is listed below.

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

#ifndef STASSID
#define STASSID "your-ssid"
#define STAPSK  "your-password"
#endif

const char* ssid = STASSID;
const char* password = STAPSK;

void setup() {
  Serial.begin(115200);
  Serial.println("Booting");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("Connection Failed! Rebooting...");
    delay(5000);
    ESP.restart();
  }

  // Port defaults to 8266
  // ArduinoOTA.setPort(8266);

  // Hostname defaults to esp8266-[ChipID]
  // ArduinoOTA.setHostname("myesp8266");

  // No authentication by default
  // ArduinoOTA.setPassword("admin");

  // Password can be set with it's md5 value as well
  // MD5(admin) = 21232f297a57a5a743894a0e4a801fc3
  // ArduinoOTA.setPasswordHash("21232f297a57a5a743894a0e4a801fc3");

  ArduinoOTA.onStart([]() {
    String type;
    if (ArduinoOTA.getCommand() == U_FLASH) {
      type = "sketch";
    } else { // U_FS
      type = "filesystem";
    }

    // NOTE: if updating FS this would be the place to unmount FS using FS.end()
    Serial.println("Start updating " + type);
  });
  ArduinoOTA.onEnd([]() {
    Serial.println("\nEnd");
  });
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  });
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) {
      Serial.println("Auth Failed");
    } else if (error == OTA_BEGIN_ERROR) {
      Serial.println("Begin Failed");
    } else if (error == OTA_CONNECT_ERROR) {
      Serial.println("Connect Failed");
    } else if (error == OTA_RECEIVE_ERROR) {
      Serial.println("Receive Failed");
    } else if (error == OTA_END_ERROR) {
      Serial.println("End Failed");
    }
  });
  ArduinoOTA.begin();
  Serial.println("Ready");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  ArduinoOTA.handle();
}

Controlling the Toy Car Robot

Controlling the Toy Car is a complicated question, with many ideas jumping into my mind, only to be pushed aside by technical issues, as well as real-world constraints on what is physically possible to be mounted on the plastic body of the toy car, space available on the inside, as well as not interfering with suspensions, springs, turning wheels etc.

The chassis of the toy car

As is clearly visible, there is really not a lot of space available here for sensors. Mounting sensors to the body will also provide a bit of a challenge, as well as won’t really look nice either…

Give an old toy car new life

I have thus decided to implement remote control for the time being, and later, maybe after 3d-printing a more suitable body, to add sensors for autonomous functionality. The ESP-Now protocol will be used extensively for the remote control, as, in my opinion, it required no additional hardware, is quite fast, as well as being extremely easy to use. It does however make it necessary to use another ESP deice in the remote control unit.

Manufacturing the PCB

The PCB for this project is currently on its way from China, after having been manufactured at PCBWay.
Please consider supporting them if you would like your own copy of this PCB, or if you have any PCB of your own that you need to be manufactured.

PCBWay

If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

Easy to Use RA-02 Breakout Module

Original RA-02 breakout Module, next to improved RA-02 breakout Module

Most Makers and electronics enthusiasts may already know of the RA-02 LoRa Module. Many of them might own an RA-02 Breakout module or two… For those who do, they will surely know about the problems encountered with using this particular breakout module…

The RA-02 module, in itself, is a great piece of kit, and when used on a custom PCB, which was designed with all the little secrets of this module taken into consideration, is a pleasure. Using the RA-02 breakout module, in its existing form factor, does however present quite a few unique challenges, which, if you are unaware of them, can cause quite a few frustrating moments, or even result in permanent damage to the module…

In this post, we will focus on :
1) The Challenges of the existing commercially available RA-02 Breakout Module
2) My Solution to above mentioned Challenges
3)Testing the Module
Maker Uno – An Arduino Uno Clone
Maker Nano RP2040
Maker Pi Pico – Raspberry Pi Pico breakout module


What are these challenges:

1) The module is based on the SX1278 chip from Semtech and is a 3v device. The IO pins are NOT 5v compatible but seem to work for a few hours or so when used with 5v… This causes many people, especially on Youtube, to assume that it is ok to send 5v logic signals to this module…

I have still not seen any Youtube video telling viewers to at least use a resister divider or logic converter… People just don’t know, and those that know seem to be keeping quiet!

Adding logic converters is in fact specified by the datasheet.

2) Adding logic converters means adding additional wiring, and for a breadboard based project, that adds to the complexity.

3) You have a total of 4 ground pins that need to be connected. not connecting all of them, causes funny things to happen, from overheating down to failure… ( My personal experience while researching this project)

4) The existing breakout module is not breadboarding compatible, resulting in a floating assembly with wires going everywhere, which results in unstable connections etc…

Basically something similar to the picture below:

RA-02 breakout Module (original) with Maker Uno and Level converter module

In this picture, I have an existing RA-02 Breakout Module, with an 8 channel Logic converter and an Arduino Uno clone, along with all the needed wiring to make this setup possible… Quite a lot of wires indeed…

My solution:

I design and use quite a few LoRa PCBs and on all of them, I implement logic conversion using the BSS138 N-MOS Mosfet and 10k resistors. It is a cheap and reliable solution, but it can take up quite a lot of space on a PCB, as this means 11 Mosfets and 22 10k resistors if I were to provide level conversion to all of the RA-02’s GPIO and IO pins…

I also have the constant problem of many unnecessary wires, many of which sometimes fail straight out of the box, when prototyping something. I partly solved that by designing a few dedicated PCB solutions, but that is not always ideal,

Using a dedicated Logic Converter IC, and Mosfet based converters to make up the difference, on a breadboard compatible module, seemed like a good idea, so I went ahead and designed the following solution:

RA-02 breakout Module on a breadboard

The breakout board module is breadboard compatible, and also has clearly marked pins to indicate the 3v and 5v sides of the module.

Testing the Module:

Using a 5v device ( Cytron’s Maker Uno )

For my first test, I decided to test with an Arduino Uno Clone, since that is what most Makers and students will have access to. I used Cytron’s Maker Uno platform, which is equipped with some added goodies, in the form of diagnostic LED etc to make prototyping a lot easier.

RA-02 breakout Module, connected to Maker Uno

As we can clearly see, It is only necessary to connect to the 5v logic side of the module, as well as provide 3v and 5v + GND to the module

In this test, I used Sandeep Mistry’s LoRa Library, with the Arduino IDE to do a quick test sketch.

Connections are as follows:

RA-02 Module Maker Uno

MISO D12

MOSI D11

SCK D13

NSS D10

RST D9

DIO0 D2

OE D8

Full code download

Let us look at some important sections though, to thoroughly understand how to use the module:

Pin Declaration

#include <SPI.h>       // include libraries

#include <LoRa.h> // I used Sandeep Mistry’s LoRa Library, as it is easy to use and understand

const int csPin = 10;     // LoRa radio chip select

const int resetPin = 9;    // LoRa radio reset

const int irqPin = 2;     // change for your board; must be a hardware interrupt pin

const int OEPin = 8;     // Output Enable Pin, to enable the Logic Converter

In the Setup function, we need to do a bit of extra work, since our Maker Uno ( or your Arduino Uno ) is a 5v device…

void setup() {

 Serial.begin(115200); // initialize serial

 pinMode(OEPin,OUTPUT); // Setup the OE pin as an Outout

 digitalWrite(OEPin,HIGH); // and Pull it High to enable the logic converter

 while (!Serial);

 Serial.println(“LoRa Duplex – Set spreading factor”);

 // override the default CS, reset, and IRQ pins (optional)

 LoRa.setPins(csPin, resetPin, irqPin); // set CS, reset, IRQ pin

 if (!LoRa.begin(433E6)) {       // initialize ratio at 433 MHz

  Serial.println(“LoRa init failed. Check your connections.”);

  while (true);            // if failed, do nothing

 }

 LoRa.setSpreadingFactor(8);      // ranges from 6-12,default 7 see API docs

 Serial.println(“LoRa init succeeded.”);

}

A comparison, using the standard RS-02 Breakout module, together with one of my own “Arduino type PCB”

ATMEGA328P with 8 Channel Logic Converter.

Original RA-02 Breakout Module, connected to an ATMEGA328P PCB with onboard Level converters

As we can see, you need quite a lot more wires to make this work. It is also worth noting that we have only 8 level converters on this ATMEGA328P PCB, in order to use all of the RA-02’s GPIO, we will need to add an additional external logic converter as well.

Using a 3v Device:

Cytron’s Maker Nano RP2040

For my second test, I decided to be a bit brave, and try to use the new Raspberry Pi Pico ( RP2040 Microprocessor ). I have quite a few of them lying around and have never really done a lot with them, due to the fact that I do not really like using MicroPython or CircuitPython, and also because the recently released Arduino Core for the RP2040 still being quite new… I decided to use a development board that I recently bought from Cytron, the Maker Nano RP2040, as it has all the added diagnostic features to make my life a bit easier, I will also include a test with an original Pi Pico board, to make it more accessible to everyone out there.

RA-02 Breakout Module, connected to Maker Nano RP2040

Once again, I used Sandeep Mistry’s LoRa Library, with the exact same Arduino sketch, used for the Maker Uno test. (I obviously needed to change the pin numbers though, as the RP2040 uses different pins for its SPI interface).

Maker Nano RP2040 RA-02 Breakout Module

NSS 17

MOSI 19

MISO 16

SCK 18

RST 9

DIO0 8

In this case, we DO NOT need the OE pin, as the RP2040 is a native 3v device. The level converter can thus stay disabled, with its pins in tri-state ( high impedance ) mode.

If we look at the code, it is similar to the Maker Uno’s code, with only the Pin declarations needing a change

#include <SPI.h>       // include libraries

#include <LoRa.h>

const int csPin = 17;     // LoRa radio chip select

const int resetPin = 9;    // LoRa radio reset

const int irqPin = 8;     // change for your board; must be a hardware interrupt pin

byte msgCount = 0;      // count of outgoing messages

int interval = 2000;     // interval between sends

long lastSendTime = 0;    // time of last packet send

// Note that SPI has different names on the RP2040, and it has 2 SPI ports. We used port 0

// CIPO (Miso) is on pin 16

// COPI (Mosi) is on pin 19

// SCK is on pin 18

// CE/SS is on pin 17, as already declared above

I did not use a breadboard, in order to make things as easy as possible.

Cytron’s Maker Pi Pico – A Pi Pico on a breakout PCB

RA-02 Breakout Module, connected to Maker Pi Pico

To make things a bit easier, without having to resort to using a breadboard, I decided to do the Original Pi Pico test using the Maker Pi Pico PCB. This PCB is basically a big breakout module, with detailed pin numbers and some diagnostic LEDs, but it also uses a native Pi Pico, soldered directly to the PCB, by means of the castellated holes… So, While technically not being a true standalone Pico, It makes my life easier and was thus used for the test, as I can be sure that the pins are labelled exactly the same as on the original Pico.

The code used for the Maker Nano RP2040 works perfectly, with no changes required.

This post is getting quite long by now, so I have decided not to include my tests of the ESP-12E ( NodeMCU ) or ESP32 development boards here as well… They also function as expected.

In Summary

When I started this project, I set out to solve a problem ( personal to me ), that could potentially help a lot of other people use the RA-02 Module for more projects and tasks. The Breakout module in its current form can also be used with the RA-01h module (915Mhz Module) without any changes. All GPIO pins are broken out, and accessible through full logic converted pins on both sides of the breakout module.

I hope that this will be useful to someone. I am also not releasing the full schematics at this stage, as I may decide to make some minor cosmetic changes in the near future.

The PCB can however be ordered from PCBWay in its current form and works 100% as expected. The BOM file is available with the ordered PCB as usual.

PCBWay Banner

This PCB was manufactured at PCBWAY. The Gerber files and BOM, as well as all the schematics, will soon be available as a shared project on their website. If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

PCBWay Start Quotation Page

4) Click on PCB Instant Quote

PCBWay Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

Quick order PCB from PCBWay

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

PCBWay PCB parameters
PCBWay PCB Parameters - Page 2

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

PCBWay Stencil
PCBWay Checkout

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

I2C IO Module with 4 Relay Outputs and 4 Galvanic Isolated Inputs

Sometimes we need extra Inputs or Outputs on a device, or for use with a project. To implement it properly we also need a lot of additional electronic components to properly isolate these inputs and outputs, with the signals they switch, from our own project, because, let us be real, electronics and electrical devices in the real world do not all work with Arduino or ESP32/ESP8266 save voltages ( 5v and 3.3v ).

I will also tell you about a very special deal to get PCBs of your own made for only one (1) USD ( Including shipping with DHL )! No, I am not joking, and I am not crazy either… More on that later in the post…


It is thus extremely important to have a module that can effectively interface with inputs of 5.5v up to 32v DC ( optically Isolated up to 3000v ), and relay outputs, also optically isolated at 3000v. ( Note that the optical isolation voltage does not mean you can input that voltage level into the chip! It means that it can isolate the electronics on the safe side of the isolator from a voltage spike of up to that voltage!).

I also love using I2C, as it allows me to add modules onto an existing data bus while using only 2 GPIO lines on the MCU!

The module I am presenting to you today was designed to be operated from 5v DC. That includes the I2C data lines (SDA and SCL). If you need to interface to a 3.3v microprocessor, like an ESP32 or ESP8266, or even the new RP2040 or an STM32, you need to use a logic level converter.

The PCB uses the popular PCF8574 8 channel IO expander, which is extremely easy to use, and where you can connect up to 8 devices in a chain ( 16 if you use the PCF8574AT variant as well.. Meaning eight of each variant) This surely adds up to quite a lot of IO lines at a cost of only 2 GPIO on your MCU!

The Circuit diagram is below, and I will discuss each part briefly.

Schematic – Page 1

This is the Galvanic Isolated Input schematic. Each input operates at a voltage of 5.5v to 32v DC. Complete Galvanic Isolation between the Module and the remote input is in effect. Please note that you have to supply a remote ground from the device that provides the input. DO NOT connect the PCB Module ground to an isolated ground pin. This may still work but renders the galvanic Isolation for that input completely useless.


Relay Driver Schematic

This is the Relay driver schematic. Each relay output is driven through an optocoupler, as well as a transistor. Although this arrangement does not provide complete galvanic Isolation of the relay coil, it does protect your MCU from any voltage spikes caused by back-emf when the relay is de-energised. The Relay contacts themselves, being magnetically actuated by the coil, are in themselves Galvanically Isolated from the rest of the PCB.

I2C Control Schematic

Finally, we have the I2C IO Expander schematic, with a 5v LDO regulator, capable of providing up to 600mA of current to the PCB. The PCF8574 Chip’s address is selectable with DipSwitch SW1 so that you can use multiple PCBs at the same time if you should choose to do so. The only note on that is that you should not connect the 5v lines of each individual PCB together. You should also only connect the GND and SDA, SCL lines back to the MCU.

Raw PCB Layout

Earlier on in the post, I promised to tell you about a very special deal…

Well, here it is, as well as some details about the sponsor of this very exciting deal…

PCBPartner.com is owned and operated by Kinji Group, which was established in 1997. We have over 20 years of experience in PCB manufacturing, PCB design, component manufacturing and distribution, PCB assembly and PCB cam software development.

While Kinji Group has 3 PCB factories in China, we have also developed strategic partnerships with more than 15 other factories around Asia. We, therefore, have a large group of specialists in PCB manufacturing, quality control, technical support and part sourcing to support your innovative ideas and products.

Our over 500 employees are spread across 8 branches in Mainland China (Shenzhen, Dongguan, Shanghai, Wuxi, Chengdu, Xiamen), Hong Kong SAR, and Taiwan. And we’re still growing!


We’re confident once you try us out, we’ll become your PCB Partner. And if not? Well, you’ll have scored some free PCB! So why not take us for a spin, you’ve got nothing to lose.

We, MakerIoT2020.com, have decided to give it a go and send this particular PCB to PCBPartner.com for manufacturing. So far, while we are still waiting to receive the PCB, ( Weekends happen 🙂 ), We are very happy with the ease of use of the online ordering system provided.

We would also like to point out that this special order will only be available until the end of March 2022,
as well as that there are a few conditions:

Promotion ends  March 31st 2022
Each new customer can enjoy free PCB on their first order
This promotion applies to
1-2 layers of FR4 PCB, up to 100x100mm, 10pcs, with Green Solder Mask
4 layer of FR4 PCB, up to 50x50mm, 10pcs, with Green Solder Mask
1 layer Aluminum PCB, up to 100x100mm, 10pcs
This PCB promotion cannot be used with other discounts or other promotional activities



For a full list of conditions, and countries that may participate in this offer, please click on the link here

Let us have a look at the entire ordering process..

Once you click on the PCBPartner.com link, you will be taken to their website, where you should sign up, which is free and easy… We used our Google.com account details and were ready to order in seconds…

PCBPartner Start Page

You can now Login with your new credentials ( after registering using this special link ). Then click on the FR4 button to start the order process…

FR4 PBC Quote Form – Before uploading your Gerber Files

Enter the specific details for the manufacturing of your PCB, and upload your Gerber files.

After uploading your Gerber Files.

Continue selecting options for your PCB order…
Make sure to select DHL shipping, to take advantage of the special 1USD option, and click on the ADD to Cart Button…

Quote added to your shopping cart.

You will now get a message that your enquiry has been submitted successfully.

Click on the “Under review” button, to see your quote status… In my case, it took about 5 minutes for the review to pass, and be able to checkout and pay for the order…

PCB order under review

Once the review has passed, you will see a pending payment,

Payment Pending

You may now click on the “Proceed to Payment” option

Add your shipping address, and choose your payment option.

At this moment in time, only two payment options are supported, Paypal ( as well as Debit and Credit cards) and Direct Bank Transfer. I believe more options will be made available in future..
Checkout with Paypal

In my case, I chose Paypal and paid by Debit card.

Enter your card details
After Payment.

After payment was made successfully, you can also check on the status of your order…

Review your order status

You can also review your order at any stage before or after payment, as well as get progress reports of the manufacturing process.

PCB Order Status.

In conclusion, I would like to say that it was quite easy to order and make payment. The Website is easy to use, and everything is clear and easy to understand. The PCB was well manufactured and seems to be quite good quality

Automate your desk- or floor-standing fan

A typical desktop oscillating fan

Desk or floor-standing fans are one of those appliances that will be present in almost every home or office. Some of the newer ones may already have remote control of some sort, while the older models won’t. It is however quite easy to do a retro-fitted controller to most of them, and at the same time, give them some (limited) intelligence.

Your typical oscillating fan does not have a lot of intelligence built-in. They normally consist of an electrical motor, with three separate windings, of varying inductance ( meaning the number of turns in the coil of wire will change the magnetic field generated, thereby changing the speed of the electric motor).

These windings have one common side, where all three of them are connected together, and the other three are separated. Normally the live wire from your mains supply (220v AC in my case) will go to this common connection. The neutral wire will go to the common of a four-position mechanical switch, with each winding going to one of positions 2,3 and 4 ( This results in a 3-speed configuration, with the first switch being off). It is also VERY important to note that this mechanical switch is hardware interlocked, meaning that ONLY one switch can be on at any given time… This is to ensure that electricity can only flow through one winding at a time. If you were to send electricity through multiple windings at the same time, the motor will still work, but not for very long…

A more modern Oscillating Fan


In order to automate an oscillating fan, we would thus need a way to switch the separate windings on and off, while preventing other windings from getting power at the same time. I chose to do this with SPST relays, as a proof of concept, and plan to design it with DPDT relays at a later stage to implement a proper hardware interlock, in addition to the software interlock implemented in the control software ( more on that later)

My requirements for the device are the following:
1) Must operate from mains power, using the existing power cord of the fan.
2) Must allow for local operation of the fan using the existing control buttons.
3) Must be able to update firmware OTA, and have WiFi connectivity for control via Home Assistant or MQTT
4) Must be capable of adding support for ESP Now protocol at a later stage
5) The fan must not have any visible modifications on the outside

The 3 speed Fan controller PCB

Taking all of my requirements into consideration, I have designed the following PCB to take care of my needs. As I do not require a lot of GPIO for this ( only 3 outputs, and 3 inputs ), I have decided to use an ESP8266-12E module from Espressif ( manufactured by AITinker, not sponsored by either company). This module is relatively cheap and has more than enough flash memory, RAM, as well as GPIO available.

Circuit Diagram – Page 1
Circuit Diagram – Page 2

As we can see, the circuit is minimal, with optical isolation on the relay drivers, a programming header, and a 3-way input for the mechanical switch.

The completed PCB, wired to the oscillating fan

As seen in the picture above, the wiring is quite simple, with the neutral wire looped to the common terminal of each relay (I had only green mains rated cable available, will replace it later with a proper white cable to keep to wiring standards). Black is live, with one wire going to the mains socket, and the other to the common of the motor coil windings. Light blue, yellow and white ( connected to the N/O terminal of the relays) corresponds to speeds 1, 2 and 3 of the fan.

At the top of the board, 3 wires go to the mechanical switch and a fourth to DC ground. (Note that there is no AC voltage on any of the switches. )

Mounting the PCB in the base of the oscillating fan

The PCB is mounted in the base of the fan while taking care to ensure that no AC cables are near the DC components. The ESP8266 chip is oriented to the side ( logo side of PCB ) to prevent interference to the WiFi signal. The mechanical switch is mounted into its original position, and its wires are routed away from any AC carrying wires to prevent interference.

It is important to note here that the firmware for the PCB was uploaded before assembly. You should NOT attempt serial uploading while the device is connected to mains power under any circumstances. ( While I have taken every precaution to ensure that AC and DC components of the circuit are separated from each other, it is just common sense to not try to upload firmware with mains connected)

The completed PCB shows the Upload port near the right top corner.

Uploading firmware:

Initial uploading of firmware can be performed by connecting a USB-to-serial adapter to the UPLOAD port and providing 5v and ground from the USB-to-serial adapter. The flash button is held down, and the board is reset, after which you can proceed with uploading, alternatively, you can also connect the DTR and RTS lines from the serial adapter to automatically reset the board and enter flash mode as needed. ( If your adapter supports this of course).

ESPHome configuration

The YAML configuration for ESPHome is listed below:

esphome:
  name: esphome-web-18df94

esp8266:
  board: nodemcuv2


# Enable logging
logger:

# Enable Home Assistant API
api:

ota:


wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Esphome-Web-18Df94"
    password: "verysecurepassword"

captive_portal:

sensor:
  - platform: adc
    pin: VCC
    name: "ESP8266 Chip Voltage"
    id: mcu_voltage
    unit_of_measurement: "V"
    device_class: "voltage"
    accuracy_decimals: 2
    update_interval: 60s
    
  - platform: wifi_signal
    name: "WiFi Signal Sensor"
    id: wifi_strength
    device_class: "signal_strength"
    unit_of_measurement: "dBm"
    update_interval: 240s

binary_sensor:
  - platform: gpio
    pin: 
      number: 12
      inverted: true
    name: "Fan Local Control Speed 1"
    id: "fan_local_1"
    icon: "mdi:fan-speed-1"
    filters:
      - delayed_on: 500ms
      - delayed_off: 500ms
    
    on_press:
      then:
        - switch.turn_on: speed1
    on_release:
      then:
        - switch.turn_off: speed1
  
  - platform: gpio
    pin: 
      number: 13
      inverted: true
    name: "Fan Local Control Speed 2"
    id: "fan_local_2"
    icon: "mdi:fan-speed-2"
    filters:
      - delayed_on: 500ms
      - delayed_off: 500ms
    
    on_press:
      then:
        - switch.turn_on: speed2
    on_release:
      then:
        - switch.turn_off: speed2
      
  - platform: gpio
    pin: 
      number: 14
      inverted: true
    name: "Fan Local Control Speed 3"
    id: "fan_local_3"
    icon: "mdi:fan-speed-3"
    filters:
      - delayed_on: 500ms
      - delayed_off: 500ms
    
    on_press:
      then:
        - switch.turn_on: speed3
    on_release:
      then:
        - switch.turn_off: speed3

switch:
  - platform: template
    name: "Fan Off"
    id: "fan_off"
    icon: "mdi:fan-off"
    lambda: |-
      if (id(speed1).state or id(speed2).state or id(speed3).state) {
        return false;
      } else {
        return true;
      }
    turn_on_action:
      - switch.turn_off: speed1
      - switch.turn_off: speed2
      - switch.turn_off: speed3
      

  - platform: gpio
    pin: 16
    interlock: &interlock_group [speed1, speed2, speed3]
    interlock_wait_time: 1000ms
    name: "Fan Speed 1"
    icon: "mdi:fan-speed-1"
    id: "speed1"
    inverted: true
    
    
  - platform: gpio
    pin: 5
    interlock: *interlock_group
    interlock_wait_time: 1000ms
    name: "Fan Speed 2"
    icon: "mdi:fan-speed-2"
    id: "speed2"
    inverted: true
    
  - platform: gpio
    pin: 4
    interlock: *interlock_group
    interlock_wait_time: 1000ms
    name: "Fan Speed 3"
    icon: "mdi:fan-speed-3"
    id: "speed3"
    inverted: true
    

Manufacturing the PCB

This PCB was manufactured at PCBWAY. The Gerber files and BOM, as well as all the schematics, will soon be available as a shared project on their website. If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

5) If you do not have any very special requirements for your PCB, click on Quick-order PCB

6) Click on Add Gerber File, and select your Gerber file(s) from your computer. Most of your PCB details will now be automatically selected, leaving you to only select the solder mask and silk-screen colour, as well as to remove the order number or not. You can of course fine-tune everything exactly as you want as well.

7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

8) When you are happy with the options that you have selected, you can click on the Save to Cart Button. From here on, you can go to the top of the screen, click on Cart, make any payment(s) or use any coupons that you have in your account.

Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.